# reflex-ghci

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Run GHCi from within a [Reflex FRP](https://reflex-frp.org) application and interact with it using a functional reactive interface.

![Screenshot](https://i.imgur.com/5y61Qx7.png)

## Library

A functional-reactive wrapper around GHCi that uses filesystem notifications to automatically reload haskell source files.

`Reflex.Process.GHCi` provides the core GHCi process-running infrastructure. If you want to run your own GHCi, directly control when it reloads, or build your own custom interface, look there.

`Reflex.Vty.GHCi` provides a few widgets that are useful when building a console GHCi interface. Use these components to assemble your own vty GHCi runner.

## Executable

This package includes a [reflex-vty](https://github.com/reflex-frp/reflex-vty)-based executable, shown above. Module information (errors, warnings, etc) is shown in a scrollable pane on the top half of the screen and the output of any expression you (optionally) choose to evaluate is shown in a scrollable pane on the bottom half. The panes are resizable using the mouse.

```bash
$ reflex-ghci -h
Welcome to reflex-ghci 0.1.4.0

Usage: reflex-ghci [-c|--command COMMAND] [-e|--expression EXPR]
  Run a Haskell REPL that automatically reloads when source files change.

Available options:
  -c,--command COMMAND     The ghci/cabal repl command to
                           run (default: "cabal repl --repl-options=-Wall")
  -e,--expression EXPR     The optional expression to evaluate once modules have
                           successfully loaded
  -h,--help                Show this help text

```

## Acknowledgements
Inspired by the fantastic [ghcid](https://github.com/ndmitchell/ghcid) project.